JP3071266B2 - Optical component axis alignment method and axis alignment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a mechanism for aligning an optical component, and more particularly, to a method for forming a part of a lens barrel, comprising a lens frame for holding an optical member such as a lens. The present invention relates to a method and a mechanism for fixing to a shaft member supporting another lens frame or the like.

[0002]

2. Description of the Related Art In recent years, for a zoom lens or the like, a guide rod as two shaft members has been used instead of a cylindrical frame for linearly guiding a lens frame for the purpose of reducing the size and weight and increasing the accuracy. , And a mechanism for moving the lens frame of each lens group forward and backward has been adopted. In this mechanism, first,
The two guide rods are positioned with respect to the optical axis of the reference frame.
They must be fixed in parallel and symmetrically.

Conventionally, a press-fitting method, a screwing method, an insert molding method, an applying method, and the like have been adopted as a method of fixing the guide rod. In the press-fitting method, as shown in FIG. 6, two fitting holes 5 provided in a mirror frame 51 in parallel with the optical axis O thereof are provided.
1a, and guide rods 52 and 53 are press-fitted into the fitting holes 51a and fixed. In the screwing method, as shown in FIG. 7, a lens frame 61 is provided with two screw holes 61a provided in parallel with its optical axis O, and the guide rod 6 is provided in the screw hole 61a.
This is a method in which 2, 63 are screwed and fixed. The insert molding method is a method of fixing the guide rods 72 and 73 by insert molding when molding the lens frame 71 as shown in FIG. Further, the applying method is as shown in FIG.
As shown in (B) of FIG.
Guide rods 82 and 83 are applied to grooves 81a having two V-shaped application surfaces provided in parallel with the optical axis O, and the L-shaped fixing plate 84 is fixed to the lens frame 81 using screws 85. In this way, the guide rods 82 and 83 are fixed to the lens frame 81.

[0004]

However, according to the conventional fixing methods described above, in any case, the accuracy of fixing the parallelism of the guide rod to the optical axis is not sufficient. That is, in the press-fitting method, it is difficult to obtain the parallel accuracy of the fitting hole 51a, and it is difficult to control the press-fit dimensional accuracy of the hole itself. In the screwing method, the screw hole 61 is used.
It is more difficult to secure the parallel accuracy of a with respect to the optical axis. In the insert molding method, even if the accuracy on the molding die can be guaranteed, due to internal stress during molding, etc.
After release, the parallelism of the guide rods 72 and 73 may be out of order. Further, in the contacting method, not only high precision is required for processing of the contact surface, but also the tip of the guide rod may swing due to a change in the contact force. According to this method, a dedicated component such as a fixing plate is required, and the material cost is increased.

The present invention has been made to solve the above-mentioned problems, is advantageous in terms of material cost, does not depend on the machining accuracy of the guide rod supporting hole, and the fixing accuracy does not depend on it. It is an object of the present invention to provide a method and a mechanism for aligning an optical component such that distortion in processing or molding does not act on a guide rod.

[0006]

According to the method of aligning optical components of the present invention, as shown in the conceptual diagram of FIG. 1, an optical axis O of a lens frame 1 constituting a part of a lens barrel, and this lens frame. In the method of aligning optical components, which is fixed at a position deviated from the optical axis O of the first optical member O and makes the axes of the shaft members 2 and 3 that guide the other lens frame in the optical axis direction parallel to the lens frame 1, On the other hand, the shaft members 2 and 3
Are loosely fitted, the optical axis and the axis of the two are made parallel by a jig 4, and then both are fixed by an adhesive 5.

Also, the axis alignment mechanism for the optical component of the present invention is provided at a position off the optical axis of the lens frame 1 in the axis alignment mechanism for the optical component, as also shown in the conceptual view of FIG. The shaft members 2 and 3 have loose fitting holes into which the shaft members 2 and 3 are loosely fitted. When the lens frame 1 is fitted to the fitting surface 4c to which the lens frame 1 is fitted and the fitting surface 4c. The jig 4 has a fitting hole 4a provided at a position overlapping with the loose fitting hole 1a and fitting the shaft members 2 and 3, and the axis of the fitting surface 4c and the fitting hole 4a are parallel to each other. In the state where the lens frame 1 and the shaft members 2 and 3 are fitted and fitted respectively, the loose fitting state of the lens frame 1 and the shaft members 2 and 3 is fixed by the adhesive 5.

[0008]

The fitting surface 4c of the jig 4 is fitted into the lens frame 1,
The fitting hole 4a and the loose fitting hole 1a are in a state of overlapping. Then, the shaft members 2 and 3 are fitted into the fitting holes 4 a of the jig 4 and further inserted into the loose fitting holes 1 a of the lens frame 1. Subsequently, an adhesive 5 is injected from an adhesive injection hole 1b provided in the lens frame 1, and the shaft members 2 and 3 are fixed to the loose fitting holes 1a of the lens frame 1. And
As shown in FIG. 2, shaft members 2 and 3 are fixed to the lens frame 1 in parallel to the optical axis O.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 3 is a longitudinal sectional view of a lens frame mechanism unit which is an axis alignment mechanism assembled based on the optical component axis alignment method according to the embodiment of the present invention. As shown in the figure, the mechanism section is a part of a lens barrel, and includes a lens frame 11 that holds an optical member such as a lens and a shaft member that supports another lens frame and the like. A certain guide rod 12, 13 is fixed by an adhesive 15 using a positioning rod jig 14 for the guide rod. That is, in the lens frame 11, a loose fitting hole 11 for loose fitting with the guide rods 12, 13 with a gap of about 0.02 to 0.05 mm in diameter.
a, and a fitting opening 11c or the like into which a fitting surface of a fitting portion 14c parallel to the optical axis O of the guide rod positioning jig 14 is fitted with almost no gap.

The loose fitting hole 11a is provided with an inlet 11b for the adhesive 15. The loose fitting hole 11
A chamfered portion 11d is provided on both end surfaces of the hole a, and a chamfered portion 11e is provided on the outer surface side of the injection port 11b. On the other hand, in addition to the fitting portion 14c, the guide rods 12 and 13 can be fitted to the jig 14 with little clearance, and two guide rod fitting holes 14a having a predetermined interval parallel to the optical axis O are provided. Is provided. The fitting portion 14c of the fitting hole 14a
As shown in the perspective view of FIG.
4d is provided. Further, knurled portions 12a and 13a for retaining are provided at portions of the guide rods 12 and 13 inserted into the loose fitting holes 11a. The knurled portions 12a and 13a may be used so as to damage the outer shape of the shaft by stamping. The opening 11c of the lens frame 11 is a portion for holding an optical member such as a lens.

In order to assemble the guide rods in the lens frame mechanism of the embodiment constructed as described above, first, the fitting portion 14c of the positioning jig 14 is fitted into the fitting opening 11c of the lens frame 11. . Then, the guide rod insertion hole 14a and the loose insertion hole 11a are maintained in a state where the axes thereof are aligned.

Subsequently, the guide rods 12, 13 are inserted through the insertion holes 14a of the positioning jig 14, and the knurled portion 1 is inserted.
2a and 13a are inserted into the loose fitting portion 11a. With the guide rods 12 and 13 held, the adhesive 5 is injected into the injection port 11.
Then, the guide rods 12 and 13 are fixed to the lens frame 11 by pouring into the gap of the loose fitting portion 11a from the position b. As the adhesive 5, for example, a cyanoacrylic adhesive having a high curing speed, a high adhesive strength, a low curing shrinkage rate and a high permeability is used. Also,
An epoxy-based UV (ultraviolet) curable adhesive may be used.

In the bonding structure of this mechanism, since the chamfered portion 11e is provided in the adhesive injection port 11b as described above, the injection of the adhesive is easy. Further, since the injection port 11b is provided at the center of the side surface, the adhesive 5
Can be spread all over the gap. Further, since the chamfered portions 11d are provided at the upper and lower ends of the loose fitting portion 11a, it is possible to prevent the adhesive 5 from protruding, and to apply a curing accelerator to the chamfered portion 11d for immediate curing. Is also possible. Further, when the above-mentioned UV-curable adhesive is used, UV can be applied to the chamfered portion 11d to perform initial curing. Also, the escape portion 1 of the positioning jig 14
4d can be used as an application port for the curing accelerator or a UV irradiation port when a UV-curable adhesive is used. Further, by providing the escape portion 14d, the adhesive can be prevented from adhering to the positioning jig 4.
Further, since the knurled portions 12a and 13a are provided on the bonding portions of the guide rods 12 and 13 as described above, the strength in the pull-out direction can be further improved. Then, the guide rods 12, 1 of the loose fitting portion 11a of the lens frame 11 are provided.
3 is 0.02 to 0.05 in diameter as described above.
A gap as small as about mm is used to reduce the degree of parallelism deviation due to the shrinkage of the adhesive upon curing. If the gap is smaller than the above-mentioned gap, the accuracy of the hole processing affects the accuracy of assembling the guide rod to the lens frame, which is not preferable.

As described above, in the lens frame mechanism of the present embodiment, the lens frame 11 does not need to be provided with the fixing portions of the guide rods 12 and 13 which require high precision, such as press-fit holes and screws. It is only necessary to provide the loose fitting portion 11a which does not need to have high precision, and the guide rods 12 and 13 are fixed to the optical axis O with high precision at the position held by the positioning jig 14. It is possible to reduce the number of assembling steps and parts costs.

In the case of the lens frame mechanism according to the above embodiment, it is possible to use the lens frame as a reference first lens frame and further assemble other second and third lens frames. FIG.
FIG. 3 shows a vertical cross-sectional view of a state where a few lens frames are assembled. The first
The lens frame 21 has a loose fitting portion 21a for the guide rods 26 and 27 and an adhesive injection port 21b. The guide rods 26 and 27 are bonded and fixed to the loose fitting portion 21a in parallel with the optical axis O. ing. The second and third lens frames 22 and 23 are provided with loose fitting holes 28 and 29 for loosely fitting with the outer shapes of the sleeves 24 and 25 fitted to the guide rod 26 without play. Fitting hole 2
8 and 29 are provided with adhesive injection ports 22b and 23b, respectively. The U-shaped grooves 22e and 23 guided straight by the guide rod 27 are provided on the opposite sides of the loose fitting holes 28 and 29.
e are provided respectively. Note that optical members such as lenses are attached to the inner peripheral openings 21c, 22c, and 23c of each lens frame.

As shown in FIG. 5, the lens frame mechanism constructed as described above is assembled with reference to the first lens frame 21 to which the guide rods 26 and 27 are bonded and fixed.
c, the cage portion 22d of the second lens frame 22 and the second lens frame 2
The seal cage portions 23d of the third lens frame 23 are respectively fitted into the second fitting openings 22c. And the sleeves 24, 25
Is inserted into each of the loose fitting holes 28 and 29 and held parallel to the optical axis O. In this state, the cyanoacrylic adhesive 2
8, 29 are injected from the adhesive injection ports 22b, 23b of the respective sleeves, and the sleeves 24, 25 are bonded and fixed to the lens frames 22, 23. In this manner, the three-group lens frame can be assembled. However, in the present lens frame structure, the second and third lens frames need to have the sleeves 24 and 25 on the optical axis O of the first lens frame. Fixed parallel to each other, it can be moved straight through the guide rods 26 and 27 in parallel to the first lens frame, and the accuracy of the optical axis between the lens frames can be improved. Become.

[0017]

As described above, the shaft aligning mechanism assembled based on the method for aligning optical components according to the present invention performs positioning of the shaft member using a jig, and performs adhesive fixing in that state. Therefore, according to the present invention, the optical axis accuracy between the lens frames is high, and further, it is not necessary to increase the processing accuracy of the shaft member supporting portion of the lens frame, and it is also possible to suppress the component cost, There are many remarkable effects such as the number of assembling steps can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing a bonding state of a shaft alignment mechanism of an optical component showing the concept of the present invention.

FIG. 2 is a longitudinal sectional view of a mechanism for aligning the optical component shown in FIG. 1;

FIG. 3 is a vertical cross-sectional view showing a bonded state of a lens frame showing one embodiment of the present invention.

FIG. 4 is a perspective view of a positioning jig used for bonding the lens barrel of FIG. 3;

FIG. 5 is a longitudinal sectional view showing a bonded state of a three-group lens frame mechanism using the lens frame of FIG. 3;

FIG. 6 is a longitudinal sectional view of a lens frame mechanism to which a guide rod is fixed by a press-fitting method, showing a conventional example.

FIG. 7 is a vertical cross-sectional view of a lens frame mechanism to which a guide rod is fixed by a screwing method according to a conventional example.

FIG. 8 is a vertical sectional view of a lens frame mechanism to which a guide rod is fixed by insert molding according to a conventional example.

FIG. 9 is a longitudinal sectional view of a lens frame mechanism to which a guide rod is fixed by an applying method according to a conventional example.

[Explanation of symbols]

1, 11, 21… Mirror frame 1a, 11a, 21a… Free-fitting hole 2, 3 ……………………… Shaft member 4 ………… ………………………………………………………………………………………………… Fitting hole 4c ……………………… Fitting surface into which the mirror frame fits. ………………………………………………………………… 12,13,26,27 ……………………………………………………………………………………………………………………………… ... Fitting hole 14c Fitting portion (fitting surface for fitting into the lens frame)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 7/00

Claims (2)

(57) [Claims] An optical axis of a lens frame forming a part of a lens barrel, and a shaft member fixed to a position deviated from the optical axis of the lens frame and guiding another lens frame in the optical axis direction. In the method of aligning an optical component to make the axis parallel, the shaft member is loosely fitted to the lens frame, and both optical axes and the axis are made parallel with a jig, and then both are fixed with an adhesive. A method of aligning an optical component, comprising: 2. An optical axis of a lens frame constituting a part of a lens barrel, and a shaft member fixed at a position deviated from the optical axis of the lens frame and guiding another lens frame in the optical axis direction. In an axis alignment mechanism of an optical component for making the axis parallel to the optical axis, the axis alignment mechanism is provided at a position off the optical axis of the lens frame, and has a loose fitting hole into which the shaft member is loosely fitted. A fitting surface to be fitted, and a fitting hole provided at a position overlapping with the loose fitting hole when the lens frame is fitted to the fitting surface, wherein the shaft member is fitted. And a fitting in which the lens frame and the shaft member are respectively fitted and fitted to a jig in which the axis of the fitting hole is parallel to the fitting hole, and then the loose fitting state of the lens frame and the shaft member is fixed with an adhesive. Axis alignment mechanism for optical components.